Humboldt Bay

Audubon California raises concerns about new proposed oyster farming project in Humboldt Bay

Conservation organization warns against potential damage to vital eelgrass and mudflat habitat.

Humboldt Bay, CA – Representatives of Audubon California this week expressed concern that a proposed new oyster operation in Humboldt Bay could cause irreparable damage to critical bird habitat, including eelgrass beds and mudflats. The new 237-acre project being proposed by the Humboldt Bay Harbor, Recreation and Conservation District is in the early stages of planning.

On January 31, the Humboldt Bay Harbor District released an announced that it was preparing an environmental impact report for its proposed new oyster operation. The public comment period on the proposal ends on March 4.

“As the Humboldt Bay Harbor District moves forward with this new project, it is vital that it properly evaluate potential risks to habitat, and do everything possible to avoid damage,” said Anna Weinstein, marine program director for Audubon California. “There is certainly a place in the bay for properly sited and sized shellfish projects, but they should be placed in areas to avoid unnecessary harms to sensitive bay habitats and wildlife.”

In 2017, Audubon California successfully opposed an expansion of a massive expansion of oyster operations into prime eelgrass habitat in Humboldt Bay. As part of that opposition, Audubon California joined with the California Waterfowl Association in a lawsuit to challenge the environmental impact report completed by the Harbor District. Ultimately, the California Coastal Commission agreed with Audubon California and its partners that the expansion of that project presented too great a danger to the bay’s eelgrass, wildlife and recreation, and approved a greatly reduced footprint for oyster operations.

Audubon California, the Redwood Region Audubon Society, the California Waterfowl Association, state and federal agencies, other conservation groups, and local community members have clearly communicated to the Harbor District that certain areas in the bay should be off-limits to new shellfish farm development.

“While this latest proposal seems to ignore the recent past, it’s not too late for the Harbor District to change course,” said Weinstein. “It can still develop an environmental impact report that includes a simple spatial plan for overall aquaculture in the bay, and a proposal to develop new projects in areas that don’t harm birds or recreation.”

Located in the far northwestern corner of California, Humboldt Bay is a globally significant Important Bird Area. Despite the relatively small size of the bay, its unusually dense eelgrass beds and expansive mudflats support the highest diversity of shorebirds on the West Coast, as well as some of the highest abundances in the western hemisphere -- over 500,000 shorebirds in spring  migration alone. It also supports up to 60% of all Pacific Black Brant, a species that is especially sensitive to disturbance and habitat loss.

Eelgrass is a key driver of bird activity in Humboldt Bay. This rare habitat is invaluable as a food resource for birds, as well as the fish and crustaceans that birds eat. Eelgrass is on the decline in much of California, and about one-third of the state’s remaining eelgrass is in Humboldt Bay.

Coastal mudflats support the highest densities of shorebirds in California. Many of the shorebirds that use these habitats – such as Long-billed Curlew, Western Sandpiper and Dunlin – are in decline. This type of oyster farming can exclude many shorebirds from feeding and resting during the critical migratory and wintering stages.

About Audubon California 

Audubon California is building a better future for California by bringing people together to appreciate, enjoy and protect our spectacular outdoor treasures. With more than 350,000 members and supporters in California and an affiliated 48 local Audubon chapters, Audubon California is a field program of the National Audubon Society. More information is available at

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